High-Dimensional Semiquantum Cryptography

• Published in: IEEE transactions on quantum engineering Vol. 1; pp. 1 - 17
• Main Authors: Iqbal, Hasan, Krawec, Walter O.
• Format: Journal Article
• Language: English
• Published: New York The Institute of Electrical and Electronics Engineers, Inc. (IEEE) 2020; IEEE
• Subjects: Cryptography; Dimensional tolerances; Entropy; Information theory; Noise tolerance; Protocol; Protocols; Quantum computing; Quantum cryptography; quantum information theory; quantum key distribution; Qubits (quantum computing); Security
• ISSN: 2689-1808; 2689-1808
• DOI: 10.1109/TQE.2020.3018133

A semiquantum key distribution (SQKD) protocol allows two users, one of whom is restricted in their quantum capabilities to being nearly classical, to establish a shared secret key, secure against an all-powerful adversary. The study of such protocols helps to answer the fundamental question of "how quantum" must a protocol be to gain an advantage over classical communication. In this article, we design a new SQKD protocol using high-dimensional quantum states and conduct an information theoretic security analysis. We show that, similar to the fully quantum key distribution case, high-dimensional systems can increase the noise tolerance in the semiquantum case. Furthermore, we prove several general security results which are applicable to other (S)QKD protocols (both high-dimensional ones and standard qubit-based protocols) utilizing a two-way quantum channel.